Palo Alto VM-Series – A critical error has been detected preventing proper boot up of the device

When creating a Palo Alto VM-Series firewall in VMware Workstation, you might be tempted to add some additional interfaces, only to find yourself in Maintenance Mode, with the error “A critical error has been detected preventing proper boot up of the device“:

The clue as to why is on the previous screen briefly, which says “Multiple network adapter types found in data interfaces. All data interfaces have to be the same type of network adapter“:

Sure enough, when we open the VM’s .vmx file, we can see that the pre-defined network adapters are VMXNET3, while any additional ones created in the Workstation GUI are E1000:

Simply modifying these additional adapters to “vmxnet3” will let you boot up as normal.